Saturday January 2 2021 Forecast (9:33AM)

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DAYS 1-5 (JANUARY 2-6)

You’ve made it to the second day of 2021! And the weather today is just as expected. Last night, precipitation arrived as snow in all areas west and north of Boston, a few flakes in the city, and generally rain to the southeast. The initial burst of snow was enough accumulate a coating to 2 inches, as expected. Here at the WHW location in Woburn Massachusetts I measured 7/10 of an inch (0.7) of snowfall before the band moved away and it ended. When precipitation returned, it was in the form of sleet then went to rain. During the overnight hours it became rain in all areas, but some of that rain was freezing on untreated surfaces north and west of Boston, especially in Worcester County where temperatures held close to or just below freezing longest while other areas warmed to the upper 30s and lower 40s pre-dawn. The hold-out areas will warm toward 40 today and any icing should melt away. The entire region is starting overcast with areas of rain and some fog today as low pressure tracks across southeastern New England, and as that low makes its way east and northeast of the region this afternoon and evening we’ll see the return of dry air and some clearing. As the temperature drops tonight, watch for the formation of black ice on untreated surfaces, into Sunday morning as well. Most of this will vanish due to dry air by later Sunday morning. Sunday will be a nice winter day, but don’t expect total sunshine as clouds will be rapidly moving back into the region in advance of the next low pressure system, which will bring its shield of precipitation into the region late Sunday and into Monday. The question with this system is its organization and battle against some dry air. It will have colder air to work with, so the snow potential extends a little further south and east than the system just before it, but at the same time it will be fighting dry air that may try to eat away at the precipitation. Some of the shorter range guidance has been insisting on an offshore intensification of this system, dragging cold air eastward and creating a snow situation with a bit more potential to it, while other guidance has had this occurring a little too far offshore to have much of an impact. No surprise that the guidance continues to struggle with these details but they should iron things out over the next few runs. In the mean time, I’ll just continue the idea from yesterday, and based on this, this is my early call on snowfall accumulation through Monday evening… No accumulation for outer Cape Cod and Nantucket, a slushy coating for Cape Ann MA, lower Cape Cod, and Martha’s Vineyard, northwestward to about Plymouth and westward along the South Coast, a coating to 1 inch from the South Shore north of Plymouth to southern RI away from the coast as well as northward to the immediate North Shore of the Boston area, 1-3 inches for the I-95 belt and the lower part of the I-495 belt south of I-90, and 3-5 inches for the I-495 belt from I-90 northward. This system will be hanging around underneath upper level low pressure offshore Tuesday and perhaps even into Wednesday (a little longer than previously expected) keeping it on the unsettled side here with the potential for rain and snow showers.

TODAY: Overcast with areas of fog & drizzle along with periods of rain this morning. Breaking clouds from west to east this afternoon. Highs 45-52. Wind E 5-15 MPH backing to N then W with higher gusts at times.

TONIGHT: Clearing. Lows 23-30. Watch for black ice formation. Wind W 5-15 MPH, diminishing.

SUNDAY: Increasing clouds. Snow, except mix/rain South Coast, arriving by the end of the day. Highs 35-42. Wind N up to 10 MPH.

SUNDAY NIGHT: Cloudy. Periods of snow except mix/rain in coastal areas. Lows 30-37. Wind NE 5-15 MPH.

MONDAY: Cloudy. Rain (mostly coast) & snow (mostly interior) may get heavier and rain may change to snow in all areas by later in the day. Highs 32-39. Wind NE to N 10-20 MPH, higher gusts.

MONDAY NIGHT: Cloudy. Snow/mix/rain tapering off to spotty and lighter. Lows 23-30. Wind N to NW 10-20 MPH, higher gusts.

TUESDAY THROUGH WEDNESDAY: Variably cloudy. Snow and/or rain showers possible. Temperatures generally 32-39. Wind N to NW 10-20 MPH, higher gusts.

DAYS 6-10 (JANUARY 7-11)

The delay in departure of the low pressure area into midweek likely delays the arrival of the next system or changes its track somewhat. Need to watch later January 8 through January 10, but this system could easily end up passing south of there region. Will keep a close eye on its evolution.

DAYS 11-15 (JANUARY 12-16)

Blocking pattern expected. Next storm threat window later January 12 through January 14.

87 thoughts on “Saturday January 2 2021 Forecast (9:33AM)”

  1. Thanks, TK…

    First on the Second!

    In fact, it’s a date palindrome!

    1-2-21

    Enjoy the weekend!

    1. Yw! I am very tardy in mentioning that you are one of my most loyal readers and I appreciate that a lot. It goes for everybody here of course but you always take that time to acknowledge every blog. It does not go unnoticed. 🙂

    1. The only issue I have is I’m not a fan of that tilted NBC map they use. Hard to read. They do rotate it up on the telecast though at least. 🙂

      It’ll be interesting to see where this one ends up.

        1. Yes. Definitely active. But we’ll have to see how one system will impact another. We see that a lot when they are fairly closely spaced.

          This is the pattern I was expecting to evolve in January. The block may be a little more powerful than anything I was expecting when I originally wrote my winter outlook, but there are always wildcards & surprises. This just makes for a longer transition to the classic La Nina set-up.

  5. Good morning and thank you TK.

    A nice coating last night before the changeover. Whitened everything. IT was snowing pretty hard for a short while.
    Looked like when it changed, it went right to rain and skipped the sleet part or if it did sleet, I missed it and it was for a very brief period.

    Not sure what to make of tomorrow night into Monday.

    My gut says too little too late with the intensification, but Euro, UKMET and RDPS all say that it is pretty close with a light to moderate event here in Eastern MA.

    12Z RDPS should be out very soon. Will look at that next. 🙂

  7. Some basic numbers from 2020 here in Taunton/Norton/BOX:

    Daily maximum: 99 on July 29
    Daily minimum: 6 on January 22, 23 and February 15

    Precipitation yearly total: 43.66
    Yearly average: 51.99

    Despite the comeback in the fourth quarter, we still fell short of the yearly mean by 8.33″ We had a very healthy 16.82 since October 1, erasing severe drought conditions.

    Sources: my records and NOW/Data from BOX

    3. I remember Bernie rayno one time saying don’t pay attention to the surface depiction, but rather pay attention to the 500 mb.

      Is this the case?

      1. I thought it might have been, but I could NOT enlarge your image, so I couldn’t know for sure, so I posted it anyway. 🙂

  16. The breaking clouds / clearing are a little ahead of schedule. And all locations in the WHW forecast area are now safely & sufficiently above freezing enough so there are no more icy areas in the locations that had it.

      1. its the basis of all the model guidance snowfall maps but snowfall ratios are never really direct 10-1.

        1. haven’t bought into anything just yet. Still monitoring, but there are signs of a possible Moderate snow event.

  23. Watching the 18Z HRRR with great interest.

    I Would not be surprised if a Winter Storm Watch was issued
    for inland areas right to the I95 belt and perhaps right to the city.
    I “think” the intensity will be there for WSW to the city. We shall see.

    2. YIKES! 3KM NAM is even worse. Like virtually NOTHING!*@*#^(!*@^#&!^@*(#&!(*@&#(*!&@(*#!*(@#^&!^@#&^!@&*#^!&*@^#*&!^@*#&^!*&@#^*&!^@#&*^!&*@#^*&!^@#&*!^@&#^!*&@^#*&!^@*#&^!*&@#^*&!^@#&^

    2. Plenty of ice on Horn Pond in Woburn – not overly thick, but there. It’s managed to not be all that warm but also not that cold in the pattern we’ve been in. Arctic air is all on the other side of the hemisphere.

    3. Lovely photo. No Ice here that I have seen. Even on the shallow marshy type areas. We do have an awesome beaver dam though

  26. Lots of cold advection stratocumulus & a gusty west northwest wind here now. Temp has been going down slowly after peaking in the middle 40s up here in the NW ‘burbs. It’s heading toward the upper 30s now and I expect these stratocu to be around for a while before clearing out later this evening.

      1. Ditto.

        In 2020, King lost his son – died of a heart attack – and daughter – died of cancer. Unimaginable pain for him and his family.

  32. Looking like a minor event for Boston & coastal areas as the temperature will be very marginal.

  34. OK, I have written this thing off. EVERTHING has gone South on us. Just brutal, but what else is new? Should have known from the get go. Just another TEASE.

      1. From NWS Norton

        Many factors are not in sync with each other to produce a
        significant event for us. First, the lack of strong high
        pressure and cold air to the north means that there will not be a strong frontogenetic forcing as with some storms. Models indicate that the upward vertical motion is weak…and not coincident with the dendritic snow growth region of -12C to-18C. Temperature profiles are marginal, especially in eastern MA and RI. Where precipitation is light, it may easily flip over to rain, cutting down amounts. In addition, some models indicate dry air that may intrude and shut off precipitation before daybreak Monday. Plus, the system is progressive while passing us, shortening the period of precipitation.

        And there you have it.

        One caveat… this is New England and stranger things have
        happened, so we need to still monitor the progress of the
        storm. If it deepens closer to the coast, it could mean more in the way of snow east of I-95. Right now, that is not expected.

        1. I completely agree. The only real watcher about this is that potential snowfall band in eastern areas. I never had a concern for this being a “big event”. The details I am working out are based on exactly what they stated.

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